Method for working up iron ores in a direct way



May 20, 1930.l P. H. LEDEBOER ETHOD FOR WORKINGKUPIRONlORES IN A DIRCT WAY Filed March 17, 12928 of iron ores in A dicated by the numeral Patented May` 20, 1930v SIGNOR TO STAALSYNDICAAT DR. LEDEBOER II, 0F THE BAGUE,

APari-:Nr OFFICE METHOD FOR WORKING UP ION CRES IN A DIRECT WAY Application mea March 17, 192s, serial No.- 262,604, and in the Netherlands maren 30,1927.

This invention relates to the working up a direct way, that is without the use of a blast furnace. The direct way has been successful in so far that the reduction of the ore could be carried dut satisfactorily in several ways, as for examplein the manufacture of sponge iron. The iron being formed however is very inflammable and great diiiiculty is met in trying to separate it. For obtaining the iron in a molten state a heating source must be applied which under prevailing circumstances does not exert a detrimental oxidizing faction and yet has the necessary temperature. To this purpose electrical heating in some way or other might be used, but in doing this any economical competition with the nowadays followed indirect methods (that is by the way of a .blast furnace, making the half finished product raw iron) is precluded.

For this reason it has been tried to use the heat from a iame. As fuel, either pulverized coal or a combustible gas was used. In order to prevent the detrimental oxidizing action, it was found necessary in both cases to very incompletely burn the fuel. In this way the caloric value of the fuel was very uneconomically utilized, while moreover it is very doubtful whether even in applying the highest preheating applicable, it' would be possible to obtain the necessary tem erature.

It is already known to apply sur ace combustion, e. g. for heating furnaces.

Considering what has been previously attempted to effect economical 'and thoroughextraction of iron from its ores and the disadvantages attending the carrying out of the old methods the present inventlon was conceived with the idea of evolving a method which may be carried out without the use of a blast furnace and enabling to obtain the iron in a molten state.

In the accompanying'drawing is shown a schematic arrangement for carrying out the invention. In this view the furnace is in- 1 and the charge brought into a molten state by the heat from theicombustion of fuel burned n the surface combustion burner 2 is indicated at 4. The

combustion gas indicated at 3 passes over the 'it caused back-firing.

material that is treated as indicated'by the arrows. The combustible mixture is admitted to the burner at 5 and the combustion gas is carried off at 6.

The invention therefore contemplates the 55 method by which the iron ore is reduced and the iron is separated in a molten state and which method is characterized by the fact that as heating source for the melting process a combustion gas is applied which possesses the necessary temperature and practically contains no free oxygen and which combustion gas is obtained by means of a burner, acting according to the principle of surface combus tion.

In general by means of surface combustion a combustion gas can be obtained which prac` tically does not contain free oxygen and is formed by complete or nearly complete combustion, because this manner of combustion has the characteristic property of rendering possible a nearly complete combustion without an excess of oxygen (air).

In spite of the fact that the combustion is localized in a certain zone, the usual surface combustion burners furnish combustion gases having a temperature which is considerably lower than the theoretical combustion temperature.

In the present day development of the surface combustion however kinds of burners are constructed by means of which it is possible to obtain combustion gases having very high temperatures which more closely approach the theoretical combustion temperature. In spite of this fact it has been possible to prevent the withdrawal of the combustion zone, which was the cause of many failures in using former constructions in that Particularly it, has appearedthat by means of burners constructed according to constructive principles of Lucke (Journal of Industrial and Engineering Chemistry 1913, page 801 and following pages)v and of Essich (Stahl und Eisen 1921, page 228 and following pages) it is possible to produce combustion gases of a temperature high enough to melt even pure iron.

In this way, in using the principle of sur-4v 10 way.

What is claimed is:

A method for working up iron ores ina direct way by reducing the ore and by separating the iron in a molten state, characterized by the fact that as heating source for the 20 melting rocess a combustion gas is a plied, having t e necessary temperature an practically containing no free oxygen, which combustion gas is obtained by means of a burner acting according to the principle of surface 25 combustion.

In testimony whereof I- have signed my name-:to this specification.

ANTOINETTE EUCHARIS ARIE stumm Leonora, so Admm'stmtrw of the estate of P. Ledeboer, do-

ceased. i 

